Power-operated tone-control mechanism



J. H. HAMMOND JR POWER OPERATED TONE CONTROL MECHANISM Filed Sept. 2, 1925 [Ililln l i ll ll li llvlilllillllb4l! Patented Apr. 3, 1928.

UNITED STATES JOHN HAYS HAMMOND, JR., OF GLOUCESTER, MASSACHUSETTS.

POWER-OPERATED TONECONTROL MECHANISM.

Application filed September 2, 1925.

This invention relates to musical instrumenls of the percussive type and more par ticularly to in'iprovements in the control of tone quality and musical dynamics of musia cal sound produced by such instruments It is one object of the present invention to provide an improved stringed musical instrument of the percussive type having means for variably controlling the amount of musical sound emitted from the instrument and an improved control device therefor.

The invention has particular reference to improved means of controlling the volume of sound which may readily be actuated by the musician with a minimum of effort on his part.

The invention has especial adaptability for use in a piano in which the percussive i0 mechanism is employed for vibrating a string and relates particularly to the use of an improved mechanism for controlling the volume of sound emitted from the instrument and to means for modifying the acll tion of the sound controlmeans at the will of the operator.

A feature of the invention is the provision of a separate source of power for actuating the tone modulators or refiectorsso that the O0 musician is relieved of the mechanical effort of operating the reflectors directly and maydevote his attention toimparting the desired ex )ression to the'music.

Other 0 jects will appear from the following description taken in connection with the accompanying drawings in which Figure 1 is a front elevation partly in section of a grand piano embodying features of the present invention with the tone reflectors in partly open position;

Figure 2 is a bottom plan view taken in section on the line 2-2 of Figure 1; and Figure 3 is a detailed view in section of the control mechanism shown in Figure 2.

Like reference characters refer to like parts in the several figures of the drawings. In the following description and claims, parts will be identified by specific names for convenience of expression, but they are in tended to be as generic in their application to similar parts or equivalent construction as the art will permit.

Referring to the drawings, there is shown a grand piano 10 having for the purpose of producing sound a plurality of tuned strings such as 11 tuned to the notes of the musical Serial. No. 54,078.

scale. It will be understood that there may he provided for each note of the musical scale one or more of such strings as may be desired. For example in the lower partof the scale a single string may be employed, in the upper part of the scale three strings may be employed for each note, and in an intermediate part of the scale two strings may be employed for each note. The strings 11 are mounted in a usual fran'1e12 in a conventional manner. This frame 12 together with the strings 11 are located above a soundi board 13; For vibrating the strings of ea fi of the notes of the scale by percussion there provided. a suitable hammer action such as 13 operatively connected to one of the keys iel: respectively of the manual of the piano. The strings are positioned within a casing '15 which is mounted on plurality of feet 16 so that the manual comprising the keys let is positioned at a convenient height above the floor. Below the manual and secured to the lower wall of the casing 15 there is provided a pedalblock 17 upon which'there is positioned a plurality of pedals, which show three in number, as at 18, 19, 20. The two right-hand pedals as seen in Figure 2 designated respectively 19 and 20 are connected to the sostenuto and loud pedal actions of the piano in a conventional manner and have no bearing on the present invention, need not be further described.

The left-hand pedal 18' is pivotally mounted in the block 17 and is operatively connected to a vertically reciprocating rod 21, the upper end of which engages one arm of a pivoted bell crank lever 22. The arran ement is such that when the pedal 18 is epressed by the musician the rod 21 is raised and the bell crank lever 22 is rotated in a counter-clockwise direction as seen'in Figure 2. K

The opposite arm of the bell-crank lever 22 is pivotally connected by means of a connecting link 23 to a primary valve member 24: slidably mounted within, a Valve casing 25.

A spring 26 having one end secured to the link 23 and the other end secured to a bracket 27 mounted on a portion of the pedal block 17 ,is provided for retracting the primary valve member 24:, the bell-crank lever 22 and the left-hand pedal 18 to thc normal position illustrated in Figure 1.

A secondary slide valve member 28 is positioned immediately adjacent the primary slide valve member 24 and is arranged to reciprocate independently thereof and within the casing 25.

The valve casing 25 is provided with an inlet chamber 30' which connnunicates with a conducting pipe 31 extending from a suitable source of power such as an air pump 32. The pump is driven in any suitable manner, as by a belt 33 and an electric motor 34. The motor 34 is connected to suitable power mains 35.

The primary slide valve member is provided with a valve port in an interdiate portion thereof which communicates with the chamber 30, and is provided with two oppositely disposed passages 41, 42 both of which are in communication with atmosphere. The secondary slide valve member is provided with two spaced ports 43, 44 separated by a partition 45. In one position of the slide valve members 24 and 28 as illustrated in Figure 3 of the drawing, the primary slide valve port 40 is opposite to and closed by the partition 45 of the secondary slide valve member. The ports 43 and 44 are then at atn'iospl ieric pressure, being in communication with atmosphere by way of the passages 41 and 42' respectively. The left-hand port 43 comnmnicateswith a conducting pipe 46 and thus in turn with the right-hand portion 4'7 of a double bellows 48, the left-haud portion 49 of which is similarly in communication by way of a conducting pipe 50 with the right-hand port 44. The double bellows 48 is mounted in fixed position on' the piano 10, and is provided with a central arm 51', the position of which is determined by the conjoint action ofthe two halves 47, 49 of the bellows. The outer endof the arm 51 is operatively connected to the secondary slide valve member by means of a pin and slot connection. A link 52 is pivotally connected to the outer end of the secondary slide valve member, and is connected at its outer end with an arm 53 whichin turn is secured to a rotatable shaft 54. The shaft 54 is journalled in spaced bearings 55, 56 mounted upon the casing 15 of the piano and extends througl'i the casing to the upper portion of the piano. The shaft 54 is provided with a fixed collar 57 for maintaining the shaft in predetermined longitudinal position with respect to its bearings. An arm 58 is afiixed to the shaft below the lower wall of the casing 15 and is pivotally connected at its outer end by a link 59 to one arm of a bell-crank lever 65 pivotally mounted on the piano casing 15, and having its other arm pivotally connected by means of a link 60 to a reciprocating connecting rod 61. Similarly there is secured to the shaft near its upper end an arm 62 the outer end of which is pivotally connected by means of a connecting link 63 to a. reciprocating connecting rod 64.

The casing 15 of the piano is provided with oppositely disposed controllable apertures as at 70, 71 and boundary walls 72 intermediate thereof. Mounted in the upper aperture 70 is a series of reflectors as at 73, therefor, serving to control the emission of sound. Each reflector 73 is preferably in the form of an (BlOl'lgttt'Qd, flat member pivota'lly mounted to rotate about its longitudinal axis, and is constructed with a layer of sound insulating material for effectively suppressing sound, and an inner face of sound reflecting material such as sheet aluminum or other sheet metal. The intermediate boundary "ails 72- of the casing also include a layer of sound absorljiing material of felt, wool or grass, and are provided on the inner surface with sound reflectingmaterial. 7

Each of the reflectors 73 is provided with an arm 75 011 its outer face and the outer ends of the arms 75 of the upper series of re fiectors are pivotally connected to the upper conuecting'rod 64'. The upper series of reflectors 73' are mounted in the upper aperture 70 and when the upper connecting rod 64 is moved to the right of Figure l, the upper reflectors eifectively close the upper aperture 70. Similarly there is mounted in the lower aperture 71 a second fleclors of like constructionjand adapted to control the emission of sound through the lower aperture. The construction of the lower group of reflectors corresponds to that of the upper group and the outer ends of the arms 75 of the lower group are pivotally connected to the lower connecting rod 61.

In operation the manual of the piano is employed by the musician in the usual way to cause vibration of the strings in accordance with the music being played. In order to produce a desired effect the pedal 18 is depressed to a desired extent. Downward movementof the pedal 18 causesthe rod 21 to be moved upwardly so as to rotate the bell crank lever 22 against the tension of the spring- 26 in a counter-clockwise direction as seen in F igure 1. The primary'slide valve member 24 is thus moved to the left ofFigure 1. This causes the port, 40 to register with the port 43 thus allowing air to pass from the pump 32 through the tube 31, chamber 30, ports 40, 48, tube 46 to the right hand bellows 47, thus inflating this bellows and causing it to move the arm 51 to the left. the left-hand bellows 49 being at this time cx hausted through the tube 50, port 44 and passage 42. As the arm 51 moves to the 'eft. it causes the link 52 also to be moved to the left thus causing rotation of the arm 53' in a counter cloclnvise direction as seen in Figure 2. This motion. is comn iunicated to the shaft 53' rotation of which causes the arm to be moved also in a counterlockwise direction. The arm 58 is operatively connected to the bell-crank lever which is also roseries oi? re tated in a counter-clockwise direction and which causes the link the right. The connecting rod 61 is thus moved to the right and thus the reflectors '73 ot the lower group ot reflectors are rotated in a counterclockwise direction as seen in Fig. l. Rotation of the shaft 5i also causes the arm (32 to be moved towards the right and this lliUVQll'lQllt is conmnmicated to the connecting rod (it thus moving the upper group of reflectors 73 in a clockwise direction.

The action just described continues so long as the movement of the pedal 18 downwardly continues as the secondary slide valve member 28 is moved a suflicient amount to cause the partition 45 to be moved towards the port ettl. When the. movement of the pedal is discontinued the secondary slide valve member 28 is moved into position. opposite the port 40 thus shutting (iii the supply of air to the bellows. During continuous movement of the primary valve member 2-} there will of course be a continuous follower movement on the part of the secondary valve member 28, since any movement of the port 40 away from the partition will result in a corresponding movement of the secondary valve member 28. This movement may con- 'tinue until the pedal 18 has been fully depressed at which time the closures will be entirely closed.

It the pianist desires to open the tone reflectors he relieves the pedal 18 of pressure thus allowing it to be lifted under the action of the spring 26 which will cause the primary slide valve member 2 k to be moved to the right thus connecting the pump 32 to the left-hand portion 49 of the bellows and will rotate the shaft 54 and the bell-crank lever in a clockwise direction thus tendingto open the tone reflectors.

In this way the pianist can. by a very slight pressure of the foot on the pedal 18, cause by means of the power bellows 4.7 and 49 a rapid action of the tone reflectors independently of the momentum or weight of the reflectors.

The invention upon which this application is based is broader than the specific embodiment shown and described for the purpose of illustrating at least one of the ways in which it may be employed. The scope of the invention is therefore to be understood as not being limited by the present specific description. I intend no limitations other than those imposed by the claims.

I claim:

1. In a musical instrument of the percussive type, the combination with an insulated body portion for effectively suppressing the sound produced by the instrument, of means for emitting a desired volume of sound from the instrument, an operating device including a fluid pump for said means, a source of 60 to be moved towards power for said device, means operatively interconnecting said' device and said power source, and a control valve for controlling the flow of fluid from the pump to said device.

2. In a musical instrument, a plurality of strings forming a sound source, a plurality of percussion hammers for causing vibration of said strings, a sound insulated casing surrounding said strings and having apertures, refiectin g devices rotatably positioned in said apertures for controlling the sound emitted therethrough, a pneumatically operated bellows for actuating said reflecting devices, a pneumatic pump, and a control valve interposed between the pump and the bellows for controlling the operation of the reflectors.

, In a musical stringed instrument, a plurality of strings tuned to the notes of the musical scale, a sounding board adjacent said strings, a substantially sound proof casing having a metal lining and surrounding said board and said strings and forming two enclosed resonating chambers, a plurality of reflecting devices for each of said resonating chambers for controlling the sound emitted therefrom, a pneumatically operated bellows for actuating said reflectors, a pneumatic pump, and a control valve interposed between the pump and the bellows for con trolling the operation of the reflectors.

l. In a musical instrument, a plurality of strings forming a sound source, a plurality of hammers for causing vibration of said strings, a sound insulated casing surrounding said strings and having apertures, a plurality of centrally pivoted metal lined reflecting devices rotatably positioned in said apertures for controlling the sound emitted therethrough, pneumatic pump means including a two-way pneumatically operated bellows operatively interconnecting the power source and said reflecting devices, a control valve included in said means to control the operation thereof, and a pedal to actuate said controller at the will'of an operator.

5. In a musical stringed instrument, a plurality of strings tuned to the notes of the musical scale, a sounding board adjacent said strings, a, substantially sound proof casing having metal lining and surrounding said board and said strings and forming two enclosed resonating chambers, a plurality of centrally pivoted metal lined reflecting devices for each of said resonating chambers for controlling the sound emitted therefrom, a pneumatically operated two-way bellows for selectively rotating said reflectors in either direction, a pneumatic pump, and a control valve interposed between the pump and the bellows for selectively controlling the movement of the reflectors.

6. In a musical instrument, a plurality of 1 tors rotatably source, means for apertures, a fluid actuated motor mocha insin for moving the reflectors, a fiuid pump for operating the motor mechanisnl, means operatively interconnecting the povver source and the motor mechanism, and control valve or controlling the interconnecting means at the will of an operator. 1

7. In a piano the combination with tuned strings for producing damped compressional Waves, a casing therefor, a pin. icy of tone reflectors rotatably positioned 111 a Wall of the casing, a fluid operated. motor for moving said reflectors into desiredposition, a control valve having a secondary slide valve member operatively connected to said motor mechanism, a pedal, and means operatively interconnecting the primary slide valve inemberwith said pedal. r

8. In a musical instrument the combinationwith a'plurality of strings tuned to the notes of the musical scale, means for vibratneeam ing said strings to produce sound, a casing surrounding said strings, a sounding board Within the casing and adjacent the strings and forming in combination with the casing a pair of resonating chambers, a plurality of tone reflectors for each of said resonating chambers, a reciprocating connecting rod for each group of tone reflectors, a shaft pivotally connected to said connecting rods for operating the same, a two-Way pneumatic bellows connected to said shaft, :1 control valve having ports, a plurality of conducting passages for conducting fluid from said valve ports pneumatic bellows respectively, a slide valve member for controlling the flow of fluid to said ports and having a positive connection to said shaft, a second slide valve member for controlling the operation of the first named slide valve member, and a pedal for actuating said second named slide valve member.

Signed at Gloucester, Mass, in the county of Essex and State of lilassachusetts, this Qlth day of August, A. l). 1925.

JOHN HAYS narnronn, Jr;

to dilierent parts of the 

